Improvement in telephone-alarm systems



C. E. BUELL. Telephone-Alarm System.

No. 221,512. Patented Nov. 11,1879.

UNITED STATES PATENT @FFIGE.

CHARLES E; BUELL, OF NEW HAVEN, CONNECTICUT.

IMPROVEMENT INTELEPHONE-ALARM SYSTEMS.

Specification forming part of Letters Patent No. 221,512, dated November 11, 1879; application filed August 6, 1879.

To all whom it may concern:

Be it known that 1, CHARLES E. BUELL, of the city and county of New Haven, State of Connecticut, have invented certain new and useful Improvements in Signaling Apparatus, of which the following is a specification.

My invention relates to signaling by electricity, and has for its object to sound or indicate calls or signals at any one of several stations in the same electric circuit without the calls being produced at any station other than the one for which they are intended.

A further object of my invention is to combine the said signaling apparatus with a system of telephone transmission.

I accomplish the object of my invention by the employment of several electro-magnets of different adjustment in the same main electric circuit, which I make operative separately by varying the tension of the circuit to a different and definite amount for each, and by holding those electro-magnets of a more delicate adjustment closed, while making operative separately those electromagnets of a higher adjustment.

The, accompanying drawing represents a side elevation of the call-bell electro-magnets M M M at the receiving-stations 1, 2, and 3, together with the switches and telephones of a telephone system, and the resistance-coils R R R and the keys K, K, and K switchblocks C, 0 and C plug P, and galvanometer Gr of a sending-station.

The call-bell magnet M at station 3 is made operative by the manipulation of the transmitting-key K, which makes and breaks the circuit through the entire resistance. The electro-magnets M and M of stations 1 and 2, being too highly adjusted, do not respond to the force charging the circuit with the entire resistance included therein.

To make the magnet M at station 2 respond, I manipulatesthe key K, which cuts 011' the resistance R and increases the force, charging the circuit sufliciently to cause the magnet M at station 2 to respond, but not sufficiently to make operative the magnet M of station 1, which only responds to the manipulation of the key K which still further adds to the force charging the circuit by cutting off both the resistance-coils R and R To make the magnet M of station 2 respond separately, I hold closed the electro magnet M of station 3 by depressing key K, or by inserting the plug 1? in the switchblock C.

To make operative the magnet M of station 1 without producing the same calls on magnets M and M of stations 2 and 3, I hold key K depressed, or insert the plug P in the switch-block C While manipulating key K By holding those electro-magnets of a more delicate adjustment closed, any reasonable number of call-bell electro-magnets can be thus made to respond separately.

An automatic electro-magnet or clock mechanism may be employed to manipulate the desired magnet.

The electro-magnets may be of different resistance as well as of different adjustment.

Any conducting resistance may be substituted for resistance-coils, and one set of transmitting apparatus may be used to control several circuits successively.

Any convenient form of switch may be used in place of those shown.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In a main electric circuit, the combination, with two or more electro-magnets of different construction or different adjustment and conducting resistances for varying the circuits tension to difl'erent and definite degrees, of means for holding those more delicately adjusted electro-magnets closed while making operative electro-magnets of a higher adjustment to separately produce calls and signals.

2. The combination, with one main electric circuit, of two or more switches, which interpose telephones in the circuit or in a fragment thereof, andtwo or more electro-magnets,which are made operative separately by holding those more delicately constructed or adjusted magnets closed, while making others to respond separately by varying the circuits ten- S1011.

3. The combination, with two or more elecnometer for adjusting the tension of a main electric circuit.

1 have hereunto subscribed my name in the presence of these witnesses this 4th day of August, A. D. 1879.

CHARLES E. BUELL.

Witnesses:

C. E. UALLENDER, G. A. UPHAM. 

